Template-based synthesis and discontinuous hysteresis loops of cobalt nanotube arrays

Huimin Zhang,Xiuli Zhang,Jinfei Zheng,Huiyuan Sun,Tianshan Wu,Zhijun Zhang

doi:10.1007/s10853-013-7554-8

Abstract

Co nanotubes were successfully prepared in the pores of anodic aluminium oxide templates using a DC electrodeposition method. The dependence of the product morphology on the applied potential was studied over the range −1.0 to −3.0 V. The results showed that the wall thickness of the nanotubes became thinner as the applied potential was reduced, and that there existed a critical potential (v c) related to the electrodeposition parameters, below or above which the electrodeposition process is dominated by kinetics and thermodynamics, respectively. The formation of nanotubes is the result of kinetics dominating the electrodeposition process. Magnetic measurements showed that the hysteresis loops of the nanotubes were discontinuous. Theoretical analysis suggested the existence of some peculiar magnetization configuration such as a vertical Bloch line, which was responsible for the discontinuity of the hysteresis loops.

Highlights

An exciting research subject in material science is the fabrication and investigation of nanostructures such as nanowires and nanotubes because of their unique properties and potential applications in various areas, such as catalysis [1], sensing [2], field emission [3], hybrid solar cells and electronic devices [4, 5]
The results showed that the wall thickness of the nanotubes became thinner as the applied potential was reduced, and that there existed a critical potential related to the electrodeposition parameters, below or above which the electrodeposition process is dominated by kinetics and thermodynamics, respectively
The synthesis of Co nanotubes has focused on anodic aluminium oxide (AAO) template-based electrodeposition because it is a convenient inexpensive technique, and modification of the AAO template is not necessary for the fabrication of nanotubes, which eliminates the introduction of impurities in the nanotubes [11]

Summary

Introduction

An exciting research subject in material science is the fabrication and investigation of nanostructures such as nanowires and nanotubes because of their unique properties and potential applications in various areas, such as catalysis [1], sensing [2], field emission [3], hybrid solar cells and electronic devices [4, 5]. The results showed that the wall thickness of the nanotubes became thinner as the applied potential was reduced, and that there existed a critical potential (vc) related to the electrodeposition parameters, below or above which the electrodeposition process is dominated by kinetics and thermodynamics, respectively.

Results

Conclusion